DOI QR코드

DOI QR Code

Analysis of Dynamic Behavior of Group Piles in Asymmetric Ground

비대칭지반에 설치된 무리말뚝의 동적거동 분석

  • Received : 2023.09.05
  • Accepted : 2023.09.26
  • Published : 2023.10.01

Abstract

Structures such as bridge columns installed on the asymmetric ground such as mountain areas and sloping ground are subject to various loads such as wind, temperature, earthquake, and etc. The pile foundation is generally applied to bridge columns on the asymmetric ground in order to stably support structures. The behavior of the pile foundation supporting bridge columns changes due to various load conditions. In particular, ground-pile-structure interactions should be studied to analyze the behavior of the pile foundation that supports bridge columns effected by dynamic loads such as earthquakes. The pile foundation installed on the asymmetric ground effected by the earthquake has the complicated dynamic interaction between the foundation and the ground due to the ground slope, the difference in soil resistance according to the shaking direction, and the ground movements. In this study, the 1g shaking table tests were conducted to confirm the effect of the slope of the sloping ground on the dynamic behavior of group piles supporting the superstructure installed at the berm of the sloping sandy soil which is the asymmetric ground. The result shows that the acceleration of the pile cap and the superstructure decrease as the slope of the sloping ground increase, and the slope of the dynamic p-y curve of the pile decrease.

산악지역 및 경사지반과 같은 비대칭지반에 설치된 교각과 같은 구조물은 바람, 온도, 지진등의 다양한 하중을 받게 된다. 비대칭지반에 설치된 교각과 같은 구조물을 안정적으로 지지하기 위해 보편적으로 말뚝기초가 많이 사용되고 있다. 교각을 지지하는 말뚝기초의 거동은 다양한 하중조건에 의해 변화하게 된다. 특히 지진과 같은 동적하중이 작용하는 교각을 지지하는 말뚝기초의 거동을 분석하기 위해서는 지반-말뚝-구조물 상호작용이 검토되어야 한다. 지진이 작용하는 비대칭지반에 설치된 말뚝기초는 지반경사, 진동방향에 따른 지반저항력 차이, 지반 변위 등에 의해 말뚝기초와 지반의 동적 상호작용은 매우 복잡해진다. 본 연구에서는 비대칭지반으로 경사사모래지반의 소단에 설치된 상부구조물을 지지하는 무리말뚝의 동적거동에 경사지반의 기울기가 미치는 영향을 확인하기 위해 1g 진동대 모형실험을 수행하였다. 그 결과, 경사지반의 기울기가 증가함에 따라 말뚝캡, 상부구조물의 가속도는 감소하는 것으로 확인되었으며, 말뚝의 동적 p-y 곡선의 할선기울기는 감소하는 것으로 확인되었다.

Keywords

References

  1. Ahn, K. K. (2003), Pile-soil-pile interaction in pile groups under lateral loading, Ph D. dissertation, Illinois Tech, Chicago, USA. 
  2. American Petroleum Institute (API) (2000), Recommended practices for planning, designing and constructing fixed offshore platforms, API Recommendation Practice 2A (RP 2A), 21th edn, Washington, DC. 
  3. Bao, N. N., Nghiem, X. T. and Kim, S. R. (2018), Evaluation of dynamic p-y curves of group piles using centrifuge model tests, Journal of the Korean Geotechnical Society, Vol. 34, No. 5, pp. 53~63 (In Korean). 
  4. Bae, J. S., Kim, J. S. and Kwon, M. J. (2009), A study on the rectangular-shaped passive row piles in inclined sand-ground by model test, Journal of the Korean Geotechnical Society, Vol. 25, No. 11, pp. 39~51 (In Korean). 
  5. Brandenberg, S.J., Wilson, D.W. and Rashid, M.M. (2010), Weighted residual numerical differentiation algorithm applied to experimental bending moment data, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 136, No. 6, pp. 854~863.  https://doi.org/10.1061/(ASCE)GT.1943-5606.0000277
  6. Haiderali, A.E. and Madabhushi, G. (2016), Evaluation of curve fitting techniques in deriving p-y curves for laterally loaded piles, Geotechnical and Geological Engineering, Vol. 34, No. 5, pp. 1453~1473.  https://doi.org/10.1007/s10706-016-0054-2
  7. Han, J. H., Ahn, S. N., Yoon, H. C. and Jung, J. W. (2021), Anlaysis of dynamic p-y curve characteristics according to mode shape of structure using shaking table tests, Journal of Korean Society Hazard Mitigation, Vol. 21, No. 5, pp. 245~250 (In Korean).  https://doi.org/10.9798/KOSHAM.2021.21.5.245
  8. Iai, S. (1989), Similitude for shaking table tests on soil-structure-fluid model in 1g gravitational field, soils and foundations, JSSMFE, Vol. 29, No. 1, pp. 105~118.  https://doi.org/10.3208/sandf1972.29.105
  9. Kim, S. h., Ahn, K. K. and Kang, H. S. (2018), Dynamic behavior of group piles according to pile cap embedded in sandy ground, Journal of the Korean Geo-Environmental Society, Vol. 19, No. 10, pp. 35~41 (In Korean). 
  10. Ko, H. Y. (1988), Summery of the State of art in Centrifuge Model Testing, Centrifuge in Soil Mechanics, Craig, James & Schofield(des), Balkema, pp. 11~18. 
  11. Kwon, S. Y. and Yoo, M. T. (2016), Parametric study of dynamic soil-pile-structure interaction in dry sand by 3D numerical mode, Journal of the Korean Geotechnical Society, Vol. 32, No. 9, pp. 51~62 (In Korean).  https://doi.org/10.7843/kgs.2016.32.9.51
  12. Matlock, H. and Reese, L.C. (1960), Generalized solutions for laterally loaded piles, Journal of the Soil Mechanics and foundations Division, Vol. 86, No. 5, pp. 63~94.  https://doi.org/10.1061/JSFEAQ.0000303
  13. Nguyen, B.N., Tran, N.X., Han, J.T. and Kim, S.R. (2018), Evaluation of the dynamic p-yp loops of pile-supported structures on sloping ground, Bulletin of Earthquake Engineering, Vol. 16, No. 12, pp. 5821~5842.  https://doi.org/10.1007/s10518-018-0428-3
  14. Reese, L.C. and Welch, R.C. (1975), Lateral loading of deep foundations in stiff clay, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 101, No. 7, pp. 633~649.  https://doi.org/10.1061/AJGEB6.0000177
  15. Suzuki, H., Tokimatsu, K. and Tabata K. (2014), Factors affecting stress distribution of a 3×3 pile group in dry sand based on three-dimensional large shaking table tests, Journal of Soils and Foundations, the japanese Geotechnical Society, Vol. 54, No. 4, pp. 699~712.  https://doi.org/10.1016/j.sandf.2014.06.009
  16. Tran, N. X., Yoo, B. S. and Kim, S. R. (2020), Dynamic interaction of single and group piles in sloping ground, Journal of the Korean Geotechnical Society, Vol. 36, No. 1, pp. 5~15 (In Korea). 
  17. Yang, E. K. (2009), Evaluation of Dynamic p-y Curves for a Pile in Sand from 1g Shaking Table Tests, Ph. D. Dissertation, Seoul National University, South Korea (In Korean). 
  18. Yang, E.K., Jeong, S.S., Kim, J.H. and Kim, M.M. (2011), Dynamic p-y backbone curves from 1g shaking table tests, KSCE Journal of Civil Engineering, Vol. 15, No. 5, pp. 813~821 (In Korean).  https://doi.org/10.1007/s12205-011-1113-0
  19. Yoo, N. J., Jun, S. H. and Hong, Y. K. (2007), Centrifuge modelling of bridge abutment foundation on the sloped ground, Journal of Industrial Technology, Kangwon Natl, Univ., Korea, No. 27 B, pp. 209~214 (In Korean). 
  20. Yoo, M.T., Choi, J.I., Han, J.T. and Kim, M.M. (2013), Dynamic p-y curves for dry sand by dynamic centrifuge tests, Journal of Earthquake Engineering, Vol. 17, No. 7, pp. 1082~1102 (In Korean).  https://doi.org/10.1080/13632469.2013.801377
  21. Yoon, J. K., Kim, D. S. and Bang, E. S. (2006), Development of site classification system and modification of design response spectra considering geotechnical site characteristics in Korea (I) - Problem statements of the current seismic design code, Journal of Earthquake Engineering, Vol. 10, No. 2, pp. 39~50 (In Korean).  https://doi.org/10.5000/EESK.2006.10.2.039